C++ accessor 和 mutator 方法有什么区别？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/9627093/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
What is the difference between accessor and mutator methods?
提问by Nawshad Farruque
How are accessors and mutators different? An example and explanation would be great.
访问器和修改器有什么不同？一个例子和解释会很棒。
回答by LeopardSkinPillBoxHat
An accessoris a class method used to readdata members, while a mutatoris a class method used to changedata members.
一个存取器是用于一个类方法读数据成员，而突变是用于一个类方法的变化的数据成员。
Here's an example:
下面是一个例子：
class MyBar;
class Foo
{
public:
MyBar GetMyBar() const { return mMyBar; } // accessor
void SetMyBar(MyBar aMyBar) { mMyBar = aMyBar; } // mutator
private:
MyBar mMyBar;
}
It's best practice to make data members private(as in the example above) and only access them via accessors and mutators. This is for the following reasons:
最好的做法是创建数据成员private（如上例所示）并仅通过访问器和修改器访问它们。这是出于以下原因：
- You know when they are accessed (and can debug this via a breakpoint).
- The mutator can validate the input to ensure it fits within certain constraints.
- If you need to change the internal implementation, you can do so without breaking a lot of external code -- instead you just modify the way the accessors/mutators reference the internal data.
- 您知道何时访问它们（并且可以通过断点对其进行调试）。
- mutator 可以验证输入以确保它符合某些约束。
- 如果您需要更改内部实现，您可以在不破坏大量外部代码的情况下这样做——相反，您只需修改访问器/修改器引用内部数据的方式。
回答by Duck
class foo
{
private:
int a;
public:
int accessA() const { return(a);}
void mutateA(const int A) { a = A;}
}
Also known as getters and setters and probably a dozen other terms.
也称为 getter 和 setter，可能还有十几个其他术语。
